Method and apparatus for attaching microelectronic substrates and support members

ABSTRACT

A microelectronic package and method for forming such packages. In one embodiment, the package can be formed by providing a support member having a first surface, a second surface facing opposite the first surface, and a projection extending away from the first surface. A quantity of adhesive material can be applied to the projection to form an attachment structure, and the adhesive material can be connected to a microelectronic substrate with the attachment structure providing no electrically conductive link between the microelectronic substrate and the support member. The microelectronic substrate and the support member can then be electrically coupled, for example, with a wire bond. In one embodiment, the projection can be formed by disposing a first material on a support member while the first material is at least partially flowable, reducing the flowability of the first material, and disposing a second material (such as the adhesive) on the first material.

BACKGROUND

Conventional microelectronic device packages typically include amicroelectronic substrate or die attached to a support member, such as aprinted circuit board. Bond pads or other terminals on the die areelectrically connected to corresponding terminals of the support member,for example, with wire bonds. The die, the support member, and the wirebonds are then encapsulated with a protective epoxy material to form adevice package. The package can then be electrically connected to othermicroelectronic devices or circuits, for example, in a consumer orindustrial electronic product such as a computer.

In one existing arrangement shown in FIG. 1A, a microelectronic devicepackage 10 a includes a support member 20 having an aperture 21. Amicroelectronic substrate 30 is attached to the support member 20 withstrips of adhesive tape 40 a. Substrate bond pads 31 are thenelectrically connected to corresponding support member bond pads 22 withwire bonds 32 that extend through the aperture 21. An encapsulant 11,which includes a suspension of filler material particles 12, is disposedover the microelectronic substrate 30 and the wire bonds 32. The sizesof the filler material particles 12 in any given package 10 a typicallyrange in a standard distribution about a selected mean value.

One drawback with the foregoing arrangement is that the filler materialparticles 12 (and in particular, the largest filler material particles12) can impinge on and damage the microelectronic substrate 30. Becausethe larger particles 12 tend to settle toward the support members 20,one approach to addressing the foregoing drawback is to increase theseparation distance between the microelectronic substrate 30 and thesupport member 20 by increasing the thickness of the tape 40 a.Accordingly, an advantage of the tape 40 a is that it can be selected tohave a thickness sufficient to provide the desired separation betweenthe microelectronic substrate 30 and the support member 20. However, adrawback with the tape 40 a is that it can be expensive to install. Afurther drawback is that the tape 40 a can be difficult to accuratelyposition between the support member 20 and the microelectronic substrate30.

FIG. 1B illustrates another existing microelectronic device package 10 bhaving a microelectronic substrate 30 attached to the support member 20with screen printed strips of epoxy 40 b. The epoxy 40 b can be easierthan the tape 40 a (FIG. 1A) to dispense on the support member 20, butcan have other problems. For example, the epoxy 40 b can apply stressesto the sides of the microelectronic substrate 30, but it may bedifficult to control how much of the sides the epoxy 40 b contacts,making it difficult to control the stress applied to the microelectronicsubstrate 30. Another drawback is that the thickness of the epoxy 40 btypically ranges from about 8 microns to about 25 microns, while in somecases the desired separation between microelectronic substrate 30 andthe support member 20 is greater than about 75 microns, for example, toavoid the particle impingement problem described above. Still anotherdrawback is that the interfaces between the epoxy 40 b and theencapsulant 11 (one located to the outside of the microelectronicsubstrate 30 and the other located beneath the microelectronic substrate30) can delaminate, which can reduce the integrity of the package 10 b.The interface located beneath the microelectronic substrate 30 can alsocreate a high stress region that can cause a crack C to form in theencapsulant 11. The crack C can damage the integrity of the wire bond32.

Another problem with both the tape 40 a and the epoxy 40 b is that thecoefficient of thermal expansion (CTE) of these components is typicallysubstantially different than the CTE of other components of the package.For example, the microelectronic substrate 30 typically has a CTE ofabout 3 parts per million (ppm) per ° C., the support member 20typically has a coefficient CTE of about 50 ppm/° C., and theencapsulant 11 typically has a CTE of from about 10-15 ppm/° C. Bycontrast, the tape 40 a and the epoxy 40 b each have a CTE of about150-400 ppm/° C. Accordingly, both the tape 40 a and the epoxy 40 b canexert substantial shear and/or normal forces on the microelectronicsubstrate 30 during thermal excursions for curing, reflow and otherprocesses. These forces can crack the microelectronic substrate 30,and/or delaminate layers from the microelectronic substrate 30 and/orthe support member 20, causing the package to fail.

SUMMARY

The present invention is directed toward microelectronic packages andmethods for forming such packages. A method in accordance with oneaspect of the invention includes providing a support member having afirst surface, a second surface facing opposite the first surface, and aprojection extending away from the first surface. The method can furtherinclude forming an attachment structure by applying a quantity ofadhesive material to the projection and connecting the adhesive materialto the microelectronic substrate with a surface of the microelectronicsubstrate facing toward the first surface of the support member and withthe attachment structure providing no electrically conductive linkbetween the microelectronic substrate and the support member. Themicroelectronic substrate and the support member can then beelectrically connected, for example, with a wire bond.

In one aspect of the invention, the projection can include anelectrically conductive material, such as copper or aluminum.Alternatively, the projection can have the same composition as theadhesive material. In another aspect of the invention, the attachmentstructure can be formed by disposing a first quantity of material on atleast one of the microelectronic substrate and the support member whilethe first quantity of material is at least partially flowable. Theflowability of the first quantity of material can be at least partiallyreduced, and a second quantity of material can be applied to theattachment structure while the second quantity of material is at leastpartially flowable. The attachment structure can then be connected tothe other of the microelectronic substrate and the support member.

In other aspects of the invention, the attachment structure can have afirst bond strength at a joint with the support member, and a secondbond strength at a joint with the microelectronic substrate, with thesecond bond strength greater than the first bond strength. The height ofthe attachment structure can be about 35 microns or more in oneembodiment, and can exceed 75 microns in another embodiment. In stillfurther aspects of the invention, the attachment structure can beconnected between two microelectronic substrates.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional view of a microelectronic device packagehaving a tape adhesive in accordance with the prior art.

FIG. 1B is a cross-sectional view of a microelectronic device packagehaving an epoxy adhesive in accordance with the prior art.

FIGS. 2A-2E illustrate a process for attaching a microelectronicsubstrate to a support member in accordance with an embodiment of theinvention.

FIGS. 3A-3E illustrate an in-line process for attaching amicroelectronic substrate to a support member in accordance with anotherembodiment of the invention.

FIG. 4 is a partially schematic isometric view of a support memberhaving attachment structures in accordance with another embodiment ofthe invention.

FIG. 5 is a cross-sectional view of a microelectronic package havingattachment structures in accordance with still another embodiment of theinvention.

FIG. 6 is a cross-sectional view of a microelectronic substrate mountedto a support member to form a package in accordance with anotherembodiment of the invention.

FIG. 7 is a cross-sectional view of two microelectronic substratesattached to each other with attachment structures in accordance withanother embodiment of the invention.

DETAILED DESCRIPTION

The present disclosure describes microelectronic substrate packages andmethods for forming such packages. The term “microelectronic substrate”is used throughout to include substrates upon which and/or in whichmicroelectronic circuits or components, data storage elements or layers,and/or vias or conductive lines are or can be fabricated. Many specificdetails of certain embodiments of the invention are set forth in thefollowing description and in FIGS. 2A-7 to provide a thoroughunderstanding of these embodiments. One skilled in the art, however,will understand that the present invention may have additionalembodiments, and that the invention may be practiced without several ofthe details described below.

FIGS. 2A-2E illustrate a process for attaching a microelectronicsubstrate to a support member to form a microelectronic package inaccordance with an embodiment of the invention. Referring first to FIG.2A, the process can include providing a support member 120 (such as aprinted circuit board) having a generally flat, planar shape with afirst surface 123 and a second surface 124 facing opposite from thefirst surface 123. An aperture 121 can extend through the support member120 from the first surface 123 to the second surface 124 to receiveconductive couplers, as described in greater detail below with referenceto FIG. 2E.

Referring now to FIG. 2B, one or more attachment structures 140 (two areshown in FIG. 2B) can be disposed on the support member 120. Eachattachment structure 140 can include a projection 141 that extends awayfrom the first surface 123. The projections 141 can be formed from anyof a variety of materials in accordance with any of a variety ofmethods. For example, the projections 141 can include a conductivematerial, such as copper or aluminum, disposed on the support member 120in a process such as a chemical vapor deposition, physical vapordeposition, or electrochemical deposition process. The projections 141can then be shaped using conventional etching techniques. Alternatively,the projections 141 can include nonconductive materials, such as asolder mask material, an epoxy material, or an adhesive strip (e.g., atape material). In one embodiment, the projections 141 can include aflowable die attach material, as described in greater detail below withreference to FIGS. 3A-3E. In another embodiment, the projections 141 canbe formed integrally with the support member 120, for example during theinitial manufacture of the support member 120. In any of theseembodiments, the projections 141 can be positioned to support amicroelectronic substrate relative to the support member 120.

FIG. 2C is a cross-sectional view of the support member 120 shown inFIG. 2B, with adhesive material portions 142 disposed on each of theprojections 141. The adhesive materials portions 142 can include aconventional die attach material, such as QMI 536, available from DexterElectronic Materials, a business of Loktite Corporation of Rocky Hills,Conn., or 2025D, available from Ablestik of Rancho Dominguez, Calif. Inother embodiments, the adhesive material portions 142 can include othermaterials. For example, the adhesive material portions 142 can includeadhesive tape strips, such as double-backed tape strips. In any of theseembodiments, the adhesive material portions 142 can be selected toadhere to both the projection 141 and a microelectronic substrate, asdescribed in greater detail below with reference to FIG. 2D.

Referring now to FIG. 2D, a microelectronic substrate 130 can beconnected to and/or carried by the attachment structures 140 bycontacting the microelectronic substrate 130 with the adhesive materialportions 142 to form a microelectronic package 110. Accordingly, theattachment structures 140 can include a first joint 143 at the interfacewith the support member 120, and a second joint 144 at the interfacewith the microelectronic substrate 130. In some embodiments, the firstjoint 143 and the second joint 144 can be selected to have differentstrengths. For example, if the support member 120, the microelectronicsubstrate 130, and/or or the attachment structure 140 have unequalcoefficients of thermal expansion (CTEs), and this mismatch is largeenough to cause the connection between the support member 120 and themicroelectronic substrate 130 to fail, it may be desirable to have thefailure occur at the first joint 143 (where the attachment structure 140joins the support member 120) rather than at the second joint 144 (wherethe attachment structure 140 joins the microelectronic substrate 130).In particular, if the attachment structure 140 can cause damage to thecomponent from which it separates, it may be desirable to confine suchdamage to the support member 120 rather than allow the microelectronicsubstrate 130 to be damaged. In one embodiment for which the strength ofthe first joint 143 is lower than the strength of the second joint 144,the projections 141 can include the QMI 536 material referred to above,and the adhesive material portions 142 can include 2025D die attachadhesive. In other embodiments, other materials can be selected for theprojections 141 and the adhesive material portions 142. In any of theseembodiments, the adhesive material portions 142 can include a materialthat is at least initially flowable and is disposed in its flowablestate on the projection 141.

In one aspect of an embodiment shown in FIG. 2D, portions of theattachment structures 140 can include electrically conductive materials,but the attachment structures 140 do not provide a conductive linkbetween the support member 120 and the microelectronic substrate 130.For example, the projections 141 can include an electrically conductivematerial while the adhesive material 142 includes an insulativematerial. In other embodiments, other portions of the attachmentstructures 140 (such as the projections 141) can be insulative so thatthe attachment structures 140 do not provide a conductive link betweenthe support member 120 and the microelectronic substrate 130. Instead,electrical communication between these components can be provided byseparate conductive couplers, as described below with reference to FIG.2E.

As shown in FIG. 2E, the microelectronic substrate 130 can beelectrically connected to the support member 120 with conductivecouplers 132, such as wire bonds. For example, the conductive couplers132 can extend between substrate bond pads 131 positioned on the lowersurface of the microelectronic substrate 130, and support member bondpads 122 positioned on the second surface 124 of the support member 120.Accordingly, the conductive couplers 132 can extend through the aperture121 of the support member 120. An encapsulant 111 can then be disposedover the microelectronic substrate 130 and at least a portion of thesupport member 120 to protect the physical and electrical connectionsbetween the microelectronic substrate 130 and the support member 120.Alternatively, the encapsulant 111 can be eliminated. For example, themicroelectronic substrate 130 and the associated electrical connectionscan be protected with a hollow cap disposed over the support member 120.

In another aspect of an embodiment shown in FIG. 2E, a distance D1between the microelectronic substrate 130 and the support member 120(i.e., the height of the attachment structure 140) can be selected toenhance the performance of the package 110. For example, in oneembodiment, the distance D1 can be selected to be greater than 25microns (the distance conventionally achievable with an epoxy bond) and,in a further aspect of this embodiment, the distance D1 can be selectedto be 35 microns or greater. In still a further aspect of thisembodiment, the distance D1 can be selected to be about 75 microns, or100 microns, or greater to reduce the likelihood for filler materialdisposed in the encapsulant 111 to impinge on and damage themicroelectronic substrate 130.

In another aspect of an embodiment shown in FIG. 2E, a distance D2 (bywhich the projection 141 extends above the support member 120), and adistance D3 (by which the adhesive material volume 142 extends above theprojection 141) can be selected in a variety of manners to achieve theoverall separation distance D1 described above. For example, D2 can berelatively large and D3 relatively small to reduce the volume occupiedby the adhesive material 142. In other embodiments, the relative valuesof D2 and D3 can be reversed. In one embodiment in which the projection141 is formed from an initially flowable material such as epoxy, thedistance D2 can have a value of from about 8 microns to about 25microns.

In yet another aspect of an embodiment described above with reference toFIG. 2E, the lateral extent of the attachment structures 140 can beselected to enhance the performance of the package 110. For example, theattachment structures 140 can be positioned only beneath themicroelectronic substrate 130, rather than extending around the sides ofthe microelectronic substrate 130 as typically occurs with someconventional epoxy bonds. An advantage of this arrangement, whencompared to some conventional epoxy bonds is that attachment structures140 can be less likely to impose damaging stresses on themicroelectronic substrate 130.

In a further aspect of this embodiment, a lateral extent W1 of theattachment structure 140 can be significantly less than a lateral extentW2 of the region of the microelectronic substrate 130 that overlaps thesupport member 120. For example, in one embodiment, W1 can have a valueof from about ⅓ to about ½ of the value of W2. A feature of thisarrangement is that the volume of the attachment structure 140 can bereduced relative to the overall volume of the encapsulant 111. Anadvantage of this arrangement is that it can reduce or eliminate damagecaused by CTE mismatch. For example, the encapsulant 111 may have a CTEthat is more closely matched to that of the microelectronic substrate130 and/or the support member 120, while the attachment structure 140may have a CTE quite different from that of the microelectronicsubstrate 130 and/or the support member 120. Accordingly, by controllingthe lateral extent W1 of the attachment structures 140, the fraction ofthe volume between the support member 120 and the microelectronicsubstrate 130 occupied by the attachment structure 140 can be reducedcompared with some conventional arrangements. As a result, theattachment structure 140 can be less likely to fail or cause themicroelectronic substrate 130 to fail when the package 110 undergoesthermal excursions. Another feature of this arrangement is that theattachment structure 140 can be recessed outwardly from the edge of theaperture 121. An advantage of this feature is that the potential highstress at the interface between the attachment structure 140 and theencapsulant 111 can be shifted outwardly and can be less likely thanexisting arrangements (such as that described above with reference toFIG. 1B) to crack the encapsulant 111.

FIGS. 3A-3E schematically illustrate a process for forming amicroelectronic package 110 generally similar to that described abovewith reference to FIGS. 2A-2E. In one aspect of this embodiment, theprocess can be performed by in-line die attach tools, such as areavailable from Datacon of Radfeld/Tyrole, Austria, or ESEC of Cham,Switzerland. In other embodiments, the process can be performed by othertools

Referring first to FIG. 3A, the process can include providing a supportmember 120 having an aperture 121. As shown in FIG. 3B, the supportmember 120 can be positioned beneath a dispense nozzle 350. The dispensenozzle 350 can dispose two quantities of a first material 345 onto thesupport member 120, while the first material 345 is in a flowable state,to form two projections 341 extending away from the first surface 123 ofthe support member 120. The projections 341 can define, at least inpart, corresponding attachment structures 340. In one embodiment, thedispense nozzle 350 can dispense a conventional die-attach material,such as QMI 536 or 2025D, described above. In other embodiments, thedispense nozzle 350 can dispose other initially flowable materials. Inany of these embodiments, the amount of the first material 345 dispensedon the support member 120 and the distance D2 by which the resultingprojections 341 extend beyond the first surface 123 can be low enoughthat the projections 341 maintain their shape without collapsing orslumping. For example, the projections 341 can have a height of fromabout 8 microns to about 25 microns in one embodiment.

As shown in FIG. 3C, the flowability of the first material 345 can bereduced or eliminated after it has been dispensed on the support member120, for example, by applying heat to the first material 345. In oneaspect of this embodiment, the first material 345 can be a thermosetmaterial and can be partially cured (e.g., to B-stage) or fully cured.In a specific aspect of this embodiment, the first material 345 can be“snap cured”, for example by exposure to elevated temperatures fromabout 150° C. to about 200° C. for a period of three seconds or less. Inother embodiments, the first material 345 can be exposed to othertemperatures and/or can be exposed for other time periods, for example,time periods of up to about ten seconds. In still further embodiments,the flowability of the first material 345 can be reduced by othermethods, for example, by cooling. In any of these embodiments, by atleast reducing the flowability of the first material 345, the material345 will tend to retain its shape and height and can more stably andsecurely support a second material, as described in greater detail belowwith reference to FIG. 3D.

Referring now to FIG. 3D, a second material 346 can be disposed on eachof the projections 341 while the second material 346 is in a flowablestate to increase the height of the corresponding attachment structures340. In one embodiment, the second material 346 can have a compositionidentical to that of the first material 345. Alternatively, the secondmaterial 346 can have a different composition than that of the firstmaterial 345. In either embodiment, the second material 346 can bedispensed on the projections 341 by the same dispense nozzle 350 thatdispensed the first material 345, or by a different dispense nozzle. Inany of these embodiments, the second material 346 can have adhesiveproperties, so as to adhere to the first material 345 and to themicroelectronic substrate 130, as described below with reference to FIG.3E.

Referring now to FIG. 3E, the microelectronic substrate 130 can beattached to the second material 346 of the attachment structures 340.The resulting package 110 can then be encapsulated after themicroelectronic substrate 130 is electrically coupled to the supportmember 120. Accordingly, the foregoing process can include sequentiallydisposing first and second flowable materials to build up attachmentstructures having heights, widths, and bond strengths generally similarto those described above with reference to FIGS. 2A-2E. The in-linearrangement of this process can result in an efficient and effectivepackage formation procedure.

In other embodiments, the attachment structures and packages describedabove with reference to FIGS. 2A-3E can have other arrangements. Forexample, referring to FIG. 4, the support member 120 can include aplurality of attachment structures 440 that are arranged in discretecolumns rather than continuous strips. Each attachment structure 440 caninclude a projection 441 formed, for example, from the first material345. Alternatively, the projections 441 can include non-flowablematerials. Each attachment structure 440 can further include a secondmaterial 346 disposed on the projection 441. The second material 346 canbe applied in a manner generally similar to any of those described abovewith reference to FIGS. 2A-3E. In one aspect of this embodiment, theattachment structures 440 can have a generally circular cross-sectionalshape and in other embodiments, the attachment structure 440 can haveother shapes. In one embodiment, the attachment structures 440 can bearranged in rows, and in other embodiments the attachment structures 440can be arranged in other patterns or arrays. In any of theseembodiments, the attachment structures 440 can be connected to acorresponding microelectronic substrate 130 (not shown in FIG. 4) in amanner generally similar to that described above.

FIG. 5 is a cross-sectional view of a package 510 having themicroelectronic substrate 130 connected to the support member 120 withattachment structures 540 in accordance with another embodiment of theinvention. In one aspect of this embodiment, each attachment structure540 can include the first material 345, the second material 346 and athird material 547. In one aspect of this embodiment, the flowability ofthe first material 345 can be reduced before applying the secondmaterial 346, and the flowability of the second material 346 can bereduced before applying the third material 547. Alternatively, the firstmaterial 345 can be replaced with a conductive or a nonconductivematerial disposed by processes generally similar to those describedabove with reference to FIG. 2B. In still further embodiments, theattachment structures 540 can include more than three sequentiallydisposed quantities of material to achieve the desired separationdistance D1 and/or other characteristics.

FIG. 6 illustrates a package 610 having a microelectronic substrate 630supported on a support member 620 in accordance with another embodimentof the invention. In one aspect of this embodiment, the microelectronicsubstrate 630 can be attached to the support member 620 with attachmentstructures 640 having characteristics generally similar to any of thosedescribed above with reference to FIGS. 2A-5. In a further aspect ofthis embodiment, the package 610 can have a “chip on board”configuration. Accordingly, the support member 620 can have a firstsurface 623 and a second surface 624 facing opposite from the firstsurface 623. The microelectronic substrate 630 can have a first surface634 and a second surface 635 facing opposite the first surface 634 andfacing toward the first surface 623 of the support member 620. The firstsurface 634 of the microelectronic substrate 630 can include substratebond pads 631 which are connected with conductive couplers 632 (such aswire bonds) to corresponding support member bond pads 622 positioned onthe first surface 623 of the support member 620. The physical andelectrical connections between the microelectronic substrate 630 and thesupport member 620 can be protected, for example, with an encapsulant, ashell, or a cap.

FIG. 7 illustrates a microelectronic package 710 having a plurality ofmicroelectronic substrates connected to each other in accordance withanother embodiment of the invention. In one aspect of this embodiment,the package 710 can include a first microelectronic substrate 730 ahaving first bond pads 731 a. A second microelectronic substrate 730 bcan be attached to the first microelectronic substrate 730 a withattachment structures 740 having configurations generally similar to anyof those described above with reference to FIGS. 2A-5. The secondmicroelectronic substrate 730 b can include second bond pads 731 bconnected to the first bond pads 731 a of the first microelectronicsubstrate 730 a with conductive couplers 732, such as wire bonds. Solderballs 733 or other conductive devices can provide for electricalcommunication to and from the package 710.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

1-95. (canceled)
 96. A microelectronic package, comprising: a firstmicroelectronic substrate; a second microelectronic substrate positionedat least proximate to the first microelectronic substrate; an attachmentstructure connected between the first and second microelectronicsubstrates, the attachment structure having a first quantity of materialdisposed on the first microelectronic substrate and a second quantity ofmaterial disposed on the first quantity of material, the attachmentstructure forming no electrically conductive link between the first andsecond microelectronic substrates; and a conductive coupler between thefirst and second microelectronic substrates.
 97. The package of claim 96wherein the first quantity of material is at least partially curedbefore the second quantity of material is disposed on the first quantityof material.
 98. The package of claim 96 wherein the first quantity ofmaterial has a thickness of from about 8 microns to about 25 microns.99. The package of claim 96 wherein the attachment structure is one of aplurality of attachment structures.
 100. The package of claim 96 whereinthe conductive coupler includes a wire bond connected between themicroelectronic substrate and the support member.
 101. The package ofclaim 96 further comprising an encapsulating material disposed around atleast a portion of at least one of the microelectronic substrate, thesupport member and the attachment structure.
 102. The package of claim96 wherein at least one of the first and second quantities of materialincludes an epoxy. 103-115. (canceled)
 116. The package of claim 96wherein at least one of the first and second quantities of materialincludes an electrically conductive material.
 118. The package of claim96 wherein at least one of the first and second quantities of materialincludes a solder mask material.
 119. The package of claim 96 whereinthe first quantity of material has a first composition and the secondquantity of material has a second composition different than the firstcomposition.
 120. The package of claim 96 wherein the first quantity ofmaterial has a first composition and the second quantity of material hasa second composition at least generally similar to the firstcomposition.
 121. The package of claim 96 wherein the first quantity ofmaterial and the second quantity of material have at least approximatelythe same composition and form a generally homogeneous attachmentstructure between the first and second microelectronic substrates. 122.The package of claim 96 wherein the first quantity of material includesa projection extending from the first microelectronic substrate, andwherein the second quantity of material includes an adhesive disposed onthe projection.
 123. The package of claim 96, further comprising asupport member carrying the first and second microelectronic substrates.124. The package of claim 96 wherein the first quantity of materialincludes an epoxy.
 125. The package of claim 96 wherein the secondquantity of material includes an epoxy.